Weighed CB 934 was dissolved in 50 ml of phosphate buffer of pH 6.6 with a vigorous mixing until it dissolved completely. Then, GSE and preservatives were dissolved in about 25 ml of phosphate buffer of pH 6.6. After that, the GSE solution was slowly added into the solution of CB 934 with a continuous stirring that was achieved by magnetic stirring at a speed of 100 rpm until a homogenous mixture was obtained. The gelling agent (Na-CMC) was added slowly under a continuous magnetic stirring. Then, the volume was increased up to 100 ml with the addition of phosphate buffer. Finally, the prepared gel was kept for 24 hours at room temperature (25°C) for a complete polymer dissolution.